[GHC] #11334: GHC panic when calling typeOf on a promoted data constructor
GHC
ghc-devs at haskell.org
Thu Jan 28 11:17:16 UTC 2016
#11334: GHC panic when calling typeOf on a promoted data constructor
-------------------------------------+-------------------------------------
Reporter: RyanGlScott | Owner: goldfire
Type: bug | Status: new
Priority: highest | Milestone: 8.0.1
Component: Compiler (Type | Version: 8.0.1-rc1
checker) |
Resolution: | Keywords: TypeInType
Operating System: Unknown/Multiple | Architecture:
Type of failure: Compile-time | Unknown/Multiple
crash | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s): Phab:D1757
Wiki Page: |
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Changes (by simonpj):
* owner: bgamari => goldfire
Comment:
> I suppose it would be reasonable to set all kind variables of kind * to
be *, and use Any for the others. We don't want to just use Any all the
time, because that wouldn't be backwards compatible and defaulting to * is
quite sensible. The other reasonable way forward is to issue an error at
`Proxy 'Con` without having more direction
I think I favour:
* Default kind vars of kind `*` to `*`
* Don't default others; instead error.
But note that if we have `{k1:k2, k2:*}` then defaulting `k2` to `*` might
mean we could then default `k1`.
We do need to do deafulting somehow because even without `PolyKinds`
consider
{{{
data T f a = MkT (f a)
}}}
We get `{f :: k -> *, a :: k}` and we can't reject the program.
Anyway, Richard, thanks for saying you'll get to it.
Simon
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11334#comment:18>
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